You have at least three options:

1. The curb gem
2. The multipart-post Net:HTTP extension
3. Calling curl from Ruby with, for example, Open3.

      1  Open3.popen3('curl  <and your parameters>') do |input, output, error|
      2      # do something
      3      end
   

Just happened to stumble upon the following article at caboo.se: Handy dynamic rspec tip.

I immediately found a way of simplifying a test case that involves testing that an ever increasing number of videos can be transcoded:

   1  require File.dirname(__FILE__) + '/helper'
   2  require File.dirname(__FILE__) + '/../lib/transcoder.rb'
   3  
   4  context "Transcoder" do
   5    
   6    Dir.glob('videos/*').each do |video|
   7      it "should support #{video}" do
   8        Transcoder.convert(video, "site/#{video}.flv")[:file_size].should > 0
   9      end
  10    end
  11  end

You can also use it to test model validations:

   1  require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')
   2  
   3  
   4  describe "Product" do
   5    @@valid_product_attributes = { 
   6        :name         => 'WTF',
   7        :description  => 'LOL',
   8        :price        => '10.0',
   9        :tax          => '22.0'  }
  10  
  11    
  12    before(:each) do
  13  
  14    end
  15  
  16    it "should create a new instance given valid attributes" do
  17      Product.create!(@@valid_product_attributes)
  18    end
  19    
  20    @@valid_product_attributes.each do |name, value|
  21      it "should not allow blank #{name}" do
  22        lambda do
  23          Product.create!(@@valid_product_attributes.except(name))
  24        end.should raise_error(ActiveRecord::RecordInvalid)
  25      end
  26    end
  27  end

You can easily extract video metadata into a hash with mplayer and Ruby:

   1  class Metadata
   2    
   3    def self.get(file)
   4      command  = "mplayer -vo null -ao null -frames 0 -identify #{file}"
   5      metadata = nil
   6      
   7      Open3.popen3(command) do |input, output, error|
   8        metadata = output.readlines.grep(/ID_.*/).collect {|name| name[3..name.length].split('=')}
   9        metadata = metadata.inject({}) {|hash, (key, value)| hash[key.to_sym] = value.chomp; hash}
  10      end
  11      
  12      return metadata
  13    end
  14    
  15  end

Then in an RSpec test do:

   1  it "should support 3gp" do
   2      metadata = Metadata.get("videos/sony_ericsson_k850i.3gp")
   3      
   4      metadata[:DEMUXER].should == 'mov'
   5      metadata[:VIDEO_FORMAT].should == 's263'
   6      metadata[:VIDEO_WIDTH].should == '176'
   7      metadata[:VIDEO_HEIGHT].should == '144'
   8    end

Note to self: metadata.demuxer would perhaps be a slightly better syntax.

First install the RSpec and ZenTest gem:

   1  $ sudo gem install rspec zentest

Next create the spec folder:

   1  $ cd project_folder
   2  $ mkdir spec

Save the following to spec/helper.rb:

   1  $LOAD_PATH.unshift File.dirname(__FILE__) + '/..'
   2  
   3  require 'rubygems'
   4  require 'spec'
   5  #require 'spec/rake/spectask' not needed, because ZenTest supports rspec now

Now create spec/transcoder_spec.rb, and add the following test to it:

   1  require File.dirname(__FILE__) + '/helper'
   2  require File.dirname(__FILE__) + '/../transcoder.rb'
   3  
   4  context "Transcoder" do
   5    setup do
   6      # Setup your stuff here
   7    end
   8    
   9    it "should support 3gp format" do
  10      Transcoder.convert("me_and_you.3gp").should == true
  11    end
  12  end

Let’s not forget the class we’re testing, put this code in lib/transcoder.rb:

   1  class Transcoder
   2    def initialize
   3    end
   4    
   5    def self.convert(file)
   6      return true
   7    end
   8  end

Note that autotest automatically looks for your code in the lib folder.

Now run the test with the zentest command:

   1  autotest

Change your files and autotest will run the test again.

Tip: Read Getting started with Autotest – Continuous Testing and Setting up autotest to use Growl on OSX for more information on how to increase your productivity.

I received the following error when installing Mongrel from the gem repository:

   1  marko@x61s:$ sudo gem install mongrel
   2  Updating metadata for 281 gems from http://gems.rubyforge.org
   3  complete
   4  Building native extensions.  This could take a while...
   5  ERROR:  Error installing mongrel:
   6  	ERROR: Failed to build gem native extension.
   7  
   8  /usr/bin/ruby1.8 extconf.rb install mongrel
   9  extconf.rb:1:in `require': no such file to load -- mkmf (LoadError)
  10  	from extconf.rb:1

The fix is to install the ruby development package:

   1  sudo apt-get install ruby1.8-dev